On the rebound

From
Amory Lovins, Rocky Mountain Institute

Your article claims that improving energy efficiency
simply makes people use more energy(This Week, 5 September, p 18).
The Khazzoom-Brookes postulate, as
this idea is called, seems to be rediscovered every decade or so. It shows that
economists’ ignorance of engineering is at least as dangerous as the
reverse.

As Clive Bates noted (Letters, 26 September, p 52), the “rebound effect” of
buying more services when efficient energy use lowers their marginal cost can be
real but is very small. For example, efficient fridges don’t make you reset the
thermostat lower so the milk freezes, nor do efficient …